As is generally well known in the railway industry, when railway cars are taken out of a train and parked at a siding or yard, the hand brakes on at least some of these cars are applied as a precaution against unwanted or unexpected movement of the cars. A typical railway car hand brake system normally consists of an apparatus for manually applying and biasing one or more brake shoes against one or more wheels of the railway car by either turning a hand wheel or pumping a ratchet handle on a hand brake mechanism attached to the railway car. The hand brake mechanism is usually either a cast or stamped metal gear housing usually attached to an outside end wall of the railway car and having a rotatable chain drum therein which can be rotated by turning the hand wheel or pumping the ratchet handle on the hand brake mechanism to wind a brake chain onto the chain drum. The other end of the brake chain normally extends through the bottom of the gear housing and is interconnected with cables or other linkage to brake shoes, such that winding of the brake chain onto the chain drum will apply tension to the brake chain and linkage as necessary to draw the interconnected brake shoes against adjacent railway car wheels and, accordingly, apply the hand brake as intended. In view of the fact that the hand brake, when applied, will put the brake chain and linkage in considerable tension, the hand brake mechanism must also include a lock means for locking the chain drum in place when the hand brake has been applied, to thereby maintain the tension in the brake chain and linkage and, accordingly, maintain the hand brake in the applied condition. Such a locking means normally comprises a ratchet wheel and pawl system within the hand brake mechanism to maintain the rotational position of the chain drum. A significant number of different hand brake mechanisms are known in the railway industry, an example of which is disclosed in U.S. Pat. No. 5,127,283, assigned to the assignee of this invention, and is incorporated herein by reference.
Although turning the hand wheel in the opposite direction may operate to release the hand brake in proportion to the extent of such turning, some ratchet wheel and pawl systems may not permit turning the hand wheel in the opposite direction. Accordingly, most hand brake mechanisms are provided with a quick release, non-spin mechanism which functions to instantly and completely release the hand brake without causing the hand wheel or ratchet handle to spin as the lock means on the chain drum is released. Such quick release mechanisms usually function by completely disengaging the chain drum from the lock means and gear mechanism for turning the chain drum. The quick release mechanism is normally activated by pivoting a hand brake release handle, the hand brake release handle being attached to a brake release shaft, which when rotated by the hand brake release handle outside of the gear housing, will disengage the chain drum from the mechanism locking it in place, thereby permitting the chain to self unwind from the chain drum. Normally, the outer end of the brake release shaft is provided with a tight-fitting lever arm type of hand brake release handle so that to release the hand brake, the handle or lever arm is merely pushed upwardly to rotate the brake release shaft (normally clockwise) as necessary to completely release the hand brake.
After the hand brake is released, and the hand brake release handle is released from manual manipulation, ideally, the hand brake release handle should return to its starting position by the force of gravity. However, due to frictional forces within the hand brake mechanism, the hand brake release handle may not return to a start position by the mere force of gravity, but often times will remain extending outwardly from the hand brake mechanism where it was when the brakeman released his grip thereon. If the brake release handle is left in that position extending outwardly from the hand brake mechanism, it can become a nuisance, or worse yet, a serious hazard. In extending outwardly from the hand brake mechanism, it may in some situations extend into the path of the ladder at the end of the railway car, or even extend beyond the edge of the railway car into the path of persons adjacent to the railway car, and thus present a hazard not only to railway personnel but also to pedestrians who may be standing or walking adjacent to such a railway car. Indeed, such a rigid lever arm extending laterally beyond the edge of the railway car would not only be hazardous to personnel, but if the car is in motion, the hazard would be greatly increased, and could even seriously damage railroad structures immediately adjacent to the track upon which such a railroad car is moving, not to mention damage which would result to the railway car itself and the hand brake mechanism attached thereto should such an extending handle strike a fixed object. Reference to FIG. 2 will illustrate one example of a prior art hand brake mechanism whereby the hand brake release handle does extend outwardly as described above.
While the hazard could be eliminated by manually forcing the hand brake release handle back to its starting position after it is utilized to effect a brake release, this often is not done by busy railway personnel, thus being inadvertently left in a position as illustrated in FIG. 2, creating the above said nuisance and/or hazard. Accordingly, what is needed is a hand brake release handle which cannot remain disposed in such a nuisance or hazardous position, but rather will return automatically to its starting position without relying on railway personnel. While the hazard could automatically be eliminated by making the brake release handle or lever arm significantly shorter so that it cannot extend outwardly by a sufficient length to be a nuisance or hazard, this would obviously also increase the moment force or torque required to effect a brake release, and could even make it impossible to effect a brake release without superhuman strength. It has also been realized that some sort of a ratcheting system could be developed for the hand brake release handle or release mechanism to eliminate the above-noted nuisance and hazards, but obviously such a ratcheting system would even further complicate the already complicated hand brake mechanism, which already includes at least one ratcheting system, and would add significantly to the cost of such a hand brake mechanism. Furthermore, such a ratcheting system would also include frictional forces therein, and would not necessarily eliminate the hazards of an outwardly extending handle or lever arm, without still requiring concerted effort by railroad personnel to assure its proper functioning and return to the starting position.